Tulip Planting Depth and Spacing: What Actually Matters

Tulip planting advice is everywhere, and much of it contradicts itself. The good news: there is a simple rule that works, and one that explains almost every tulip disappointment.

The three-times-height rule

Plant a tulip bulb three times its own height deep, measured from the base of the bulb to the soil surface. A typical 5 cm tulip bulb therefore goes in at 15 cm. Large exhibition varieties go to 20 cm; small species tulips to 10 cm.

Why depth decides whether tulips come back

Shallow planting is the number one reason tulips turn blind in year two. A bulb near the surface is exposed to summer heat and winter frost, both of which damage the developing flower inside. Deep planting keeps the bulb at a stable temperature and protects it from soil heaving during freeze-thaw cycles.

If you only change one thing about how you plant tulips, plant them deeper than you think you should.

Spacing

• Bedding displays: 10–12 cm apart. Tight enough for impact, loose enough that bulbs are not touching.
• Naturalising in grass: 15–20 cm apart in irregular drifts. Tulips in lawns need room to multiply.
• Pots: bulbs can almost touch — 2–3 cm apart — for a dense container display. Use a deep pot, at least 25 cm.

Which end goes up?

The pointed tip goes up. If you cannot tell, plant the bulb on its side — roots will grow downward regardless, and the stem will find its way. Tulips are forgiving on orientation and unforgiving on depth.

Soil preparation

Tulips demand drainage. On heavy clay, add a 5 cm layer of grit at the bottom of the planting hole, or plant in raised beds. Standing water in winter rots bulbs faster than cold ever will.

Should you lift them?

In zones 3–7, tulips can stay in the ground year-round if drainage is good. In zones 8+, dig and store them after the foliage dies back — summer soil temperatures are too high for most garden tulips to survive dormant.

Planting calendar

Plant tulips later than most other bulbs — November into December in mild climates. Tulips are less prone to rot than daffodils and benefit from cold soil. Late planting also reduces the risk of early sprouting.

A note on squirrels

Squirrels dig up shallow bulbs. Deep planting alone solves most of the problem. If they persist, lay chicken wire flat over the bed just below the soil surface.

Shop tulip bulbs for both bedding and naturalising varieties.